Electroluminescent panels, lamps, and displays are light-emitting media for use in many applications. Electroluminescent (EL) panels are essentially a capacitor structure with an inorganic phosphor sandwiched between two electrodes. The resistance between the two electrodes is almost infinite and thus direct current (DC) will not pass through it. When an alternating voltage is applied, the build-up of a charge on the two surfaces effectively produces an increasing field (called an electric field) energizing the phosphors and resulting in the emission of light. The increase in voltage in one direction increases the field and this causes a current to flow. The voltage then decreases and rises in the opposite direction. This also causes a current to flow. The net result is that current flows into the electroluminescent panel and thus energy is delivered to the panel. This energy is converted to visible light by the inorganic phosphor, with little or no heat produced in the process. Application of an alternating current (AC) voltage across the electrodes generates a changing electric field within the phosphor particles, causing them to emit visible light. By making one or both of the electrodes so thin, transparent or translucent that light is able to pass through and be emitted to the environment, an optically transmissive path is available.
One particular area in which electroluminescent panels can be useful is in lighted advertising displays at the point of product purchase. In today's competitive global environment, local customization of the advertising display is often desirable to accommodate language nuances, local regulations, and cultural mores. Prior art displays are fabricated to depict a predetermined graphic or text, and thus are not amenable to situations where dynamic messages need to be displayed. This makes local customization very costly and/or impractical, with long lead times when changes in the message are needed. Additionally, producing small volumes of a display containing a fixed message can be costly, due to the cost of tooling.